Intentional release of native species undermines ecological stability

Proceedings of the National Academy of Sciences, Journal Year: 2023, Volume and Issue: 120(7)

Published: Feb. 7, 2023

The massive release of captive-bred native species (“intentional release”) is a pervasive method to enhance wild populations commercial and recreational species. However, such external inputs may disrupt the sensitive interactions that allow competing coexist, potentially compromising long-term community stability. Here, we use theory data stream fish communities show intentional destabilizes dynamics with limited demographic benefit enhanced Our predicted intensifies interspecific competition, facilitating competitive exclusion unenhanced otherwise stably coexist. In parallel, excessive input individuals suppressed natural recruitment via intensified within-species competition. Consequently, ecological reduced density unstable temporal dynamics. Consistent this prediction, showed greater fluctuations fewer taxonomic richness in rivers intensive hatchery salmon—a major fishery resource worldwide. findings alarm current overreliance on accelerate global biodiversity loss undesired consequences for provisioning ecosystem services.

Language: Английский

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Bending the curve of global freshwater biodiversity loss: what are the prospects?

Biological reviews/Biological reviews of the Cambridge Philosophical Society, Journal Year: 2024, Volume and Issue: unknown

Published: Sept. 2, 2024

ABSTRACT Freshwater biodiversity conservation has received substantial attention in the scientific literature and is finally being recognized policy frameworks such as Global Biodiversity Framework its associated targets for 2030. This important progress. Nonetheless, freshwater species continue to be confronted with high levels of imperilment widespread ecosystem degradation. An Emergency Recovery Plan (ERP) proposed 2020 comprises six measures intended “bend curve” loss, if they are widely adopted adequately supported. We review evidence suggesting that combined intensity persistent emerging threats become so serious current projected efforts preserve, protect restore inland‐water ecosystems may insufficient avert losses coming decades. In particular, climate change, complex harmful impacts, will frustrate attempts prevent from already affected by multiple threats. Interactions among these limit recovery populations exacerbate declines resulting local or even global extinctions, especially low‐viability degraded fragmented ecosystems. addition impediments represented we identify several other areas where absolute scarcity fresh water, inadequate information predictive capacity, a failure mitigate anthropogenic stressors, liable set limits on biodiversity. Implementation ERP rapidly at scale through many dispersed actions focused regions intense threat, together an intensification ex‐situ efforts, necessary preserve native during increasingly uncertain climatic future which poorly understood, emergent interacting have more influential. But implementation must accompanied improve energy food security humans – without further compromising condition Unfortunately, political policies arrest environmental challenges change do not inspire confidence about possible success ERP. parts world, Anthropocene seems certain include extended periods uncontaminated surface runoff inevitably appropriated humans. Unless there step‐change societal awareness commitment biodiversity, established methods protecting bend curve enough continued degradation loss.

Language: Английский

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Impact of human intervention and predator–prey dynamics on ecosystem virus transmission

Chaos An Interdisciplinary Journal of Nonlinear Science, Journal Year: 2025, Volume and Issue: 35(1)

Published: Jan. 1, 2025

Humans and predators occupy dominant positions in ecosystems are generally believed to play a decisive role maintaining ecosystem stability, particularly the context of virus transmission. However, this may not always be case. By establishing some transmission models that cover both human perspectives predators, we have drawn following conclusions: (1) Controlling vaccination activities from perspective can potentially lower rate improve herd immunity, thereby indirectly protecting unvaccinated risk groups. (2) In ecosystem, does determine spread viruses. Once ecological balance between prey is disrupted, there scenarios where predator populations die out, overpopulate, or go extinct. such cases, has little impact, system cannot restore itself new equilibrium state. case, even if humans intervene, it difficult change fate species extinction. (3) situations maintain stable state, attitudes actions critical. Human intervention directly affect recovery hosts, rapidly reducing infection mitigating harm caused by virus. If do remain infected for long time, posing serious threat ecosystem.

Language: Английский

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Ecological non-equilibrium and biological conservation

Biological Conservation, Journal Year: 2023, Volume and Issue: 286, P. 110258 - 110258

Published: Sept. 8, 2023

How to establish efficient conservation actions and policies for the long-term persistence of ecological systems remains a challenge. Conservation biology was born as discipline crisis, targeting recovery altered ecosystems under paradigms equilibrium stability. However, we argue that concepts balance still hinder wildlife managers from optimizing proper decision-making correctly prioritizing actions. This is case, despite prevailing paradigm has recently shifted more realistic view non-equilibrium dynamics in ecosystems, even absence anthropogenic impacts. The challenge policymakers now greater. First, because basis Darwinian adaptive response hence maintaining variance, rather than decreasing it, should be target conservation. Secondly, show non-linear responses (e.g. transients critical transitions), which hamper diagnosis prediction. Even though are unable suggest solutions this conundrum, warn here about potential biases when conserving ecosystems. We insights island ecology medical science may helpful dealing with applied Incorporating advances complex into conceptual framework management policymaking also contribute improving prioritization actions, especially regarding some agents global change. Finally, advocate strengthening feedback between ecologists (both theoretical empirical) practitioners improve our knowledge on how respond perturbations.

Language: Английский

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Phenotypic Sorting of Pink Salmon Hatchery Strays May Alleviate Adverse Impacts of Reduced Variation in Fitness‐Associated Traits

Ecology and Evolution, Journal Year: 2025, Volume and Issue: 15(1)

Published: Jan. 1, 2025

ABSTRACT Maladapted immigrants may reduce wild population productivity and resilience, depending on the degree of fitness mismatch between dispersers locals. Thus, domesticated individuals escaping into populations is a key conservation concern. In Prince William Sound, Alaska, over 700 million pink salmon ( Oncorhynchus gorbuscha ) are released annually from hatcheries, providing natural experiment to characterize mechanisms underlying impacts populations. Using dataset > 200,000 sampled 30 8 years, we detected significant body size phenological differences hatchery‐ wild‐origin spawners, likely driven by competitive during maturation broodstock selection practices. Variation in traits was reduced hatchery fish, raising biodiversity concerns. However, phenotypic locals were positively correlated. We discuss possible that explain this pattern how it adverse associated with trait variation. This study suggests domestication widespread, but local adaptation be maintained sorting.

Language: Английский

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Assessing Japanese Eel Populations in a River System Using eDNA: Seasonal Variation and Modest Effectiveness of Stocking Where Natural Recruitment Is Restricted

Aquatic Conservation Marine and Freshwater Ecosystems, Journal Year: 2025, Volume and Issue: 35(3)

Published: March 1, 2025

ABSTRACT Japanese eel, Anguilla japonica , is a highly endangered species in the Western Pacific region despite its high commercial value fisheries. To enhance fisheries resources of this catadromous fish, eel stocking programs are conducted annually many rivers across Japan. These involve capturing naturally recruited glass eels at river mouths, farming them artificial ponds and releasing into rivers. However, impact these efforts on populations remains unclear. Recently, environmental DNA (eDNA) has emerged as an effective tool for assessing biomass target aquatic environments. This study aims to evaluate spatiotemporal changes population over 3 years effect using species‐specific eDNA marker Shigenobu River system western Japan, where numerous sediment‐control dams weirs present, both upstream downstream barriers. Our results show that concentration was significantly correlated with density captured eels, confirming effectiveness assays stock assessment. concentrations, well biomass, were higher than upstream. After stocking, concentrations increased remained elevated sites natural recruitment blocked by dams. Seasonal variation most pronounced downstream, occurs. findings suggest enhances areas restricted, but modest compared recruitment. Therefore, ecosystem‐based habitat management, including restoration connectivity, should be prioritized conservation.

Language: Английский

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Density- and size-dependent mechanisms modulate the outcome of stocking in a naturally recruiting freshwater piscivore (northern pike, Esox lucius): A replicated whole-lake experiment

Fisheries Research, Journal Year: 2023, Volume and Issue: 267, P. 106799 - 106799

Published: Aug. 20, 2023

Language: Английский

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A Review of Pacific Salmon Hatcheries in British Columbia, Canada, and Interactions With Natural Populations

Fisheries, Journal Year: 2024, Volume and Issue: 49(7), P. 303 - 318

Published: April 30, 2024

Pacific salmon Oncorhynchus spp. hatcheries in British Columbia (BC) have been the major activity of Salmonid Enhancement Program since 1977. However, present diminished abundance and loss fisheries BC called for a review hatchery effectiveness. The Salmon Foundation conducted resulting 15 reports publicly available on marine science website. includes evaluations effectiveness production, evidence interactions with natural populations (including rebuilding hatchery-produced salmon), future opportunities via genomics. Beyond estimation juvenile production contribution to catches spawning escapements, ability assess was limited. assessments provided few examples positive outcomes, but most were negative. lack comparative purely wild seriously limits interpretations hatchery–wild interactions. Future require more quantitative integrated salmon, open data sharing public or research, related studies could benefit from application new genomic technologies. This paper presents recommendations address these needs calls regularized reviews its net value sustainability BC's salmon.

Language: Английский

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Anglers as citizen scientists: a case study of resource monitoring in stream salmonids

Ichthyological Research, Journal Year: 2024, Volume and Issue: unknown

Published: Sept. 28, 2024

Language: Английский

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Risk v. reward for responsive movements by a highly mobile fish species in a flow-constrained and barrier-laden river

Marine and Freshwater Research, Journal Year: 2024, Volume and Issue: 75(15)

Published: Oct. 16, 2024

Context Understanding the movement behaviour of flow-dependent fish species is a foundational principle underlying effective management highly modified riverscapes. Aims To determine how variations in river discharge and instream barriers affect residency, survival golden perch (Macquaria ambigua) degraded Gwydir River system within northern Murray–Darling Basin. Methods We monitored 25 acoustic-tagged for up to 3 years by using linear array spanning ~180 km main channels across lower system. Key results Golden were largely sedentary extended periods, with movements constrained barrier maze that now defines High flows facilitated passage over barriers, highest periods activity occurring spring early summer, lesser extent autumn. Conclusion Our findings are indicative isolated population likely be neither source nor sink, but effect false sink perpetuated re-stocking practices. Implications The rehabilitation community other systems similarly poor condition throughout Basin will require major institutional societal change.

Language: Английский

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